She had her first baby six months ago (Image: krissydonners/Instagram)

Their rep branded the claims "a crock of s**t" and said it was "fake social media news" - which did little to quell the fiery speculation.

But behind the scenes it's been Beckham's sister who's been having the real relationship problems, a source claims.

"Joanne and Kris have had a really tough few months," a source told the Sun .

"Looking after a newborn knocked them for six and dealing with the constant exhaustion and worry put a huge strain on their relationship."

They are now said to be focusing on being "the best solo parents they can possibly be".

David Beckham's sister Joanne gave birth to her first baby (Image: joannebeckham/Instagram)

They have separated

Since rumours of a rift, both Posh and Becks put on a united front at a fashion dinner and have been posting plenty of loved-up pictures of themselves with their family - Brooklyn, Romeo, Cruz and little Harper.

But Victoria did confess she finds it really difficult to juggle work with the demands of a growing family, especially when it comes to working on her marriage.

"I try really, really hard. I try hardest to be the best mother," she said.

Mirror Online has contacted David Beckham's representative for comment.